This is kind of a strange way to use the terms, if you think about other things called theories in science. For instance, atomic theory, heliocentric theory, q

This is kind of a strange way to use the terms, if you think about other things called theories in science. For instance, atomic theory, heliocentric theory, quantum theory, the theory of relativity, chemical collision theory, cell theory, the germ theory of disease, the kinetic theory of gases, the theory of plate tectonics... "Proved" a theory, is actually a way of talking about that theory "proving useful." If you dump a ton of energy into a small particle in a cyclotron, you will observe that its speed "maxes out" at the speed of light, but that this does not appear to be due to some sort of friction force or anything; the energy is still extractable in collisions. If you therefore say that cyclotrons have proven special relativity, I don't think that's an abuse of language. Yes, strictly speaking what you mean is that special relativity proves useful for explaining what happens in cyclotrons, but that's not particularly a reach.